I've been doing cardio for years and I'm pretty "die-hard" at it. Not only do I train at a high intensity, but I also go for the length of the workout. For some reason, I've always had it in my head that I need to do cardio for at least 60 min. and that's what I've been doing all along. My workouts usually happen 3-5 times a week (I often *aim* for every day in the week, but it's simply not realistic, I suppose, due to time and physical endurance constraints).
Sometimes I feel so overwhelmed with the amount of cardio training I force myself to do that I often get into the all-or-nothing thinking and don't do it at all. I realize that it's better to do even 20 min. than nothing, but when I'm at the gym, if I stay on a machine for only half an hour, I really feel that I shouldn't have come at all and that I might as well make it a whole hour so that it counts for something. The amount of calories burned in half an hour, it seems, is negligible and the fat burning, from what I understand, does not even begin before 20 min. Even regardless of this (I'm not trying to lose weight per se, though I wouldn't mind getting my body fat percentage down. I just want to keep fit and prevent weight gain), I want to train for endurance and it seems that I need to prove to myself that I can keep going for at least an hour, otherwise I'm a failure.
Anyway, my point is that I don't always have the time and the energy (mental or physical) to train for a whole hour. In addition to stretching, ab work, and sometimes some sauna/steam room time, this takes up a good two hours of my time, which is quite a bit, especially after a long day at work. The time limit on cardio machines at my gym is 30 min... I know most people only do that much cardio. I'm wondering if anyone has had any weight loss and general fitness success by doing cardio training for only half an hour at a time. I realize it would have to be combined with weights, which I already do, but not often enough, since cardio always takes priority with me... It's probably all in my head but I have a love-hate relationship w/ it and I can't live w/o it...
Please feel free to share your experiences and provide some specific examples, numbers, etc.
1) INTERVAL TRAINING
2) CIRCUIT TRAINING
3) More Variety
Most experts say that 20-30 minutes of cardio is enough, especially if you're adding intervals and strength training. It's really NOT recommended to do cardio everyday. It leads to burnout, and your muscles find ways to do it with less exertion (and less benefit). Your body needs a rest to replenish itself. Also, your muscles need a day off in between tough workouts in order to do the repair work that creates stronger bigger muscles.
You can accomplish much more if you add intervals to your workout. Intervals are crucial to help train your heart, and you can burn more calories in the same amount of time. (Note: the machines aren't programmed to measure the extra calories burned during intervals, because they're measuring speed not heart rate. But it works.) After your warmup, go at your normal pace for 5 minutes or so, then raise the level for 1-2 minutes, then go to a lower than normal level for a couple minutes, then back to your normal level. You can do this several times. Most cardio machines have a programmed option for intervals, or you can control it yourself. (Read up on it). If your gym offers a spin class, try it because they're great at intervals.
You can also add more cardio benefit to your strength training by organizing your workout in circuits... alternating relatively short periods of cardio and strength training. It enables you to fit in your strength training without letting your heart rate slow too much in the process. Your heart rate will remain higher than normal for quite a while after you work out. You can add to this benefit by bringing it back up periodically between strength training or ab exercises. If you have to spend too much time sitting between sets, or waiting for a machine, spend a minute running in place or jump roping to get your heart rate back up. You get the heart benefits of a longer period of cardio, while doing other things. It's the ultimate in multi-tasking.
Skip cardio for a day and just do strength training and stretching. You can get more benefit from your strength training if you really focus on specific muscles for that day, without fatiguing them all first with the cardio.
Vary your activities as much as possible. Your muscles get accustomed to doing the same thing, and it's not as beneficial. If you normally walk or run on a treadmill, spend a day walking on the ground or street. It uses slightly different muscles, and adds benefit to your workout.
NOTE: I'm far from my peak now (I had back and knee problems for the last few years). But when I was working out the most, I lost 40-50 pounds in about a year. I almost NEVER did more than 40 minutes of cardio in one day, and I didn't really diet after the first month. (Though I fit in some extra walking because I worked at a college with a terrible parking problem.) I started at 5-6 days a week, but then settled into a 4-5 day/week schedule. I think the strength training and general conditioning helped me the most, because it raised my metabolism. It also made me feel strong and confident, even though I never reached the weight levels that the younger woman seemed to do.